Hi Bluesy.
I must say I can't quite figure out your problem exactly.
Is it that you're having trouble with STRUMMING as such or is it more a case of single notes?
Also, maybe you could post up a recording so we can get a better idea of where the problem lies?
I can't give you any advice re the electronic metronome since I only use an online one, however as for playing faster, well, there's a saying that
in order to play faster you have to start slower ... or something like that.
So start with your metronome slow and focus on getting it right, rather than focusing on speed. It can be frustrating but it's better than chasing your tail.
Anyhoo, let us know exactly what you're having trouble with and we'll hopefully point you in the right direction.